Mixing apparatus



W. A. PERVIER MIXING APPARATUS May 10, 1932.-

Filed Jan. 1

2 Sheets-Sheet 1 Kg nmwzzjz May 10, 1932. w. A. PERVIER MIXING APPARATUS 2 Sheets-Sheet 2 Filed Jan. 3, 1951 Patented May 10, 1932 umren STATES PATeN-r owl-c mtmm a: PEB IEB OF WATEBTQWN, MASSACHUSE$T$, ASSIGNQB e0 cesarean Pee-mem or M lW LE messae vsa rs a mxme APPARATUS.

A pli ati n fi e an y ,3 3 er a .9- 9$'3. .1-

This invention relates to apparatus for mining or compounding materials of elther a solid or liquid character, or ingredients comprising both liquids' and sol-ids, for example, medicinal preparatlons, dental amalgams,

etc.

It is the object of this invention to provide a serviceable and eflicient power-driven mixer having an agitator maintained in cooperative relation with a receptacle, and means for producing, between the two, relative motion whereby materials. disposed in the receptacle will be quickly and homogeneously compounded or mixed. It is a further object of this invention to provide an apparatus of this character with means for automatically controlling the duration of the operation, whereby the same may :be carried on for a predetermined period of time-or number of i cycles.

-Eurtherzobjects and advantages will be apparent as attributesof-the constructionand operationofjthe apparatus herein described and shown in the accompanying .drawings which exemplifyia recommended embodiment o the invention. a

In the drawings:

Fig. 1 is ,aside elevation, partly in section, a a m w -drive ix Fig. 2=is a plan viewiof-t he same 7 Fig.3 isasectional elevation of-the transm s ionechan m; and

Fig. 4 shows the paracentric paths or con,- vo lutions defined by .the relative movement between the mortar and pestle.

' The particular embodiment of the invention chosen for ;the purpose of illustration comprises abasel providedwith-a rear portionupon which amQtOrQ is mounted anda' front portion having a marginal .fiange ;3 whichthe housing or casinggt engages. The housing 1 comprises ;a box-like casting within which disposed a transmission gearing and a mechanism associated with aswitch? device and actuated by the transmission gearing for automatically -.eontro1ling the operation ofthe-apparatus.

The top of the-housing is providedwith a socket-;5, anopening- G having vertically -proj ec-ting and. depending flanges 7 and:.8, and a disposed crankpinQS Which engages the link second flanged opening 9. The rear wall of the housing is provided with an opening through which the driving shaft 11 pro 'ect's', said shattbeing connected mule shaft of the motor coupling 12. The end Wall is provided with asuit'able opening 13 for the reception of an actuating :lever' associated with the switch. The ,transmissiongearing comprises a di fi erential worm and gear inee-ha nism, the worm 14 beingmounted on the shaft 11 which-is supported :by the hanger 15. "The hang r comprises a block of metal having a recess intermediate its ends (shown by the; dotted line, Fig. and a centrally disposed dependingboss 16 to which :is-secured a 'horizontally extending ar1nl7. The hanger is secured to the top of the housing by' bo'lts or machine screws 18 and-l9. The arm 17 isprovided with a bearing in which one endfofshaft21isjournaled. The

gears 22 and 23 are mounted on the shaft 21: and each engages the worm 14. These gears have the :same diameter but a di-fierential number of teeth whereby one has a'posit ive rotation relative-to the other. gear 23 is pinned to shaft 21 andis' rotatable therewith. Thelupper gear 22 is pinned to the .collarsZgt which is provided with a hofrizontally projecting slotted arm or yoke 25,

the gear, collarand arm being rotatable about the shaft :21. "The collar '24 passes through the flanged opening-9 atthe topof thehou'sing andfis providedwith a'fia'ngedendor hub which enga-gesythe flange c'ircumjaeent the. opening :'9, -thus; providing a bearing surface. The gears 22land 23 are provided-"with hubs engaging respectively the depending flange circumjacent :the opening-9 and thebearing surface of arm- 'A'washer 26 may be interposed'between 'theihub of gear and the bearing surface of arm The end ofshasft 2 1 adj aeent'tothe top; of the housin'g is provided with a flangeQ'T on which ismounted an oflset or eccentrically 29. The pin 31 is securedto-the movable plate 32 and projects downward-1y through an opening in the lin k 29 into'the slot of yoke:=25. "Thus theg ear 22;-im-parts a trans" atingimotion tothe .pin 31' and causes the The lower plate 32 to move in a circular path about shaft 21 as an axis, and the gear 23 by virtue of its differential relation to gear 22 imparts a cam-like motion to the link 29. The resultant of these two movements, thus imparted to the plate 32, causes the same to travel in a paracentric or spiral path. As shown in Fig. 4 this path is endless; alternately its spirals outwardly through five revolutions, as shown by the solid lines, and then inwardly through five revolutions, as shown by the broken lines.

The operation of the apparatus is con trolled by a switching device associated with a mechanism actuated bythe gear 22. The device shown in Figs. 1 and 2 comprises a bell crank pivotally secured to a block of insulating material 41 mounted on the base 1. The arm 42 of the bell crank is insulated from the arm 43 by a fiber washer 44 and is spaced from the block 41 by a washer 45. The free end of arm 43 engages a lever 46 by means of a lug carried by the latter, the lever 46 being pivotally secured tothe block ;41. A contact 47 mounted on the lever 46 is adapted to engage the fixed contact 48 which lies in the path of movement of contact 47, the fixed contact being secured to the block by bracket 49 or other suitable means.

Electrical conductors51 enter the housing through opening 52 and are connected with the contacts and motor in any suitable manner (not shown). A spring or other suitable means (not shown) preferably is associated with the lever 46 normally retaining the same in the position shown in Fig. 2, thus holding the contactsapart to provide an open circuit which may be closed by means hereinafter more fully described. i

The arm 42 is provided with an extension or lever 53 pivotally secured tov its free end as indicated by numeral 54.. The lever 53 carries a stud 55 adapted toengage or mesh with the worm gear 56. The switch device order to cause the stud 55 to engage the worm gear 56 it will necessitate an outward movement of the arm 53, causing the bellcrank to actuate the lever 46 to close the-circuit.

x-The relationship thus established is maintained so long as the stud 55 is heldin engagement with the worm gear 56. The spring 57 is secured to the arm 42 and one end or portion thereof engages the lever 53 and urges the same downwardly and inwardly so that when the stud 55 becomes disengaged from the worm gear 56 the lever will drop to the base, thus permitting the circuit (which is closed when the stud 55 is in engagement with the worm 56) to be opened, thus shutting ofi? the motor.

The worm gear 56 is mounted on the end of shaft 61 which is jo'urnaled in the bracket 62, the other end 'of the shaft being'journaled in bearing. 63 which is secured to the top of the housing. The worm gear 56 is actuated by the star wheels 64 and 65, the former being mounted on shaft 61 and the latter on a stud shaft 66 which is secured to the top of the housing and ofiset in relation to shafts 21 and 61, as shown in Fig. 2. The wheel lies in a horizontal plane intermediate that of the wheel 64 and the gear 22 (as shown in Fig. 1) and is so disposed that its addendum circle intersects a portion of the circular path defined by the revolution of the vertically projecting pin 67 carried by gear 22 and underlies'a portion of the addendum circle of wheel 64. Thus the pin 67 engages one of the teeth on the wheel 65 during each revolution of the gear 22 and causes the same to be intermittently rotated, and the pin 68 mounted on one of the teeth of wheel 65 during each revolution likewise engages one of the teeth of wheel 64 and thus causes the worm gear 56 to be intermittently rotated. Consequently it requires a definite number of revolutions of the gear 22 to cause a single revolution of the worm 56 and, for a given speed of the motor, it requires a fixed time for the worm gear 56 to be intermittently rotated.

By using a worm gear having a pitch corresponding to a unit of time or multiple thereof re uirecl for a given operation, it is possible (for a given ratio of teeth in the star wheels) to set the lever 53 so that the stud 55 will engage or mesh with the worm gear at a point thereon corresponding to a desired period of time whereby the operation will be automatically terminated at the expiration of the desired period. Obviously such a mechanism could be designed to carry on the operation for a longer or shorter time by varying either the ratio of the teeth of the star wheel, the pitch of the worm gear, or both.

A scale 70 is secured to the wall of the housing adjacent to the opening 13 and is graduated in time units, e. g., minutes, corresponding to the teeth of the worm gear 56. By raising the lever 53 to a height corresponding to a given period of time, as shown by the scale, the stud 55 engages a tooth on the worm gear and (by maintaining a closed circuit as previously explained) causes the operation to be carried on for the desired period.

For holding the mortar and pestle in cooperative relation with each other, a preferred construction is shown in Figs. 1 and 2 comprising a bracket 71 slidably mounted on the cylindrical support 72. The support is mounted on the housing with its stepped end projecting into the opening 6 and firmly secured therein by the set screw 73 carried by the depending flange 8. The pestle 74 is secured in the socket-like holder 75 which is connected with the sleeve 76 by the web 77. The sleeve 76 has a free sliding fit about'the upright support 72 permitting the bracket. to be raised and lowered whereby the'pestle 88 secured to the bracket and also the locking member or latch 89'. The cupped member 88 is provided with a cylindrical passage in which is received the free end of the upright spindleQl which is mounted in the socket 5'. The locking member or latch 89 comprises a lever received in a suitable slot 92 in the upright '52, the lower end of the lever being pivotally secured to the upright as shown in Fig. 1. The upper end ofthe lever has a knob93 or other means providing a shoulder which is adapted to engage the top of the sleeve 76 of the bracket thereby to limit its upward movement. The spring 94, disposed in a horizontally extending recess, urges the lever 89 outwardly into locking engagement with the bracket when the latter is disposed in the position shown by the solid lines in Fig. l. The coiled spring 95, circumposed about the sleeve 7 6' intermediate the web 71 and collar 81, is under compression when the mortar and pestle are in operative engagement and thus serves to limit the downward movement of the bracket. During the mixing operation the cupped member 88 prevents the bracket from rotating about the upright 72 and any vertical movement of the bracket is limited by the locking member 89' and spring 95.

One end of the movable plate 32 slidably engages the link 29' and is supported thereby, the pin 31 holding the plate in fixed re lation thereto. The opposite end of the plate is provided with an elongate slot 7 8' through which the upright support 72 passes. The beaded marginal portions 79 adjacent to the slot slidably engage the top of flange 7 which supports this end of the plate. Vertical movement of the plate is prevented by the collar 81 which has a pressed fit about the upright 72.

A holder 82 for the mortar 83 is mounted on the plate 32 and preferably comprises a plurality of similar symmetrically disposed circumferentially spaced resilient fingers 8s projecting from the plate 85 which is secured v to the plate 32 by the horizontally disposed fingers 86. This construction not only provides a simple and effective means for firmly holding the mortar which will permit the same to be easily removed and replaced, but

also permits a universal tipping movement of the mortar and a yielding engagement between the mortar and pestle. The resilient arm 101 secured at one end to the web 77 engages the cap 102 of the holder? 5. As the pestle preferably has a slight vertical movement in the holder, the arm 101 yieldingly resists any upward movement (the downward movement being limited by the engagement with the mortar) and thus provides an additional means for maintaining the mortar and: pestle in yieldingengagement- This feature is particularly advantageous when the apparatus is used for' grinding or pulverizing in that it prevents large particles from; jamming or wedging between: the engaging surfaces and thus insures asmooth and even operation. i

In using this appara-tusthe bracket is first raised to the position shown by the broken, lines in Fig. 1 and the pestle is swungxorit. of

position, as shown by the dot and dash lines.

of Fig. 2. The materials to be mixed, ground-,- or otherwise treated are then placed in the mortar. The pestle is then brought into operative engagement with the mortar by swinging: the bracket so that the opening in the cupped member aligns with the spin..- dle and. then lowering the bracket until th e spindle passes into the opening of the cupped member and the latch 89 snaps intolocking engagement with the sleeve of the bracket; The lever 53 is pressed outwardly and raised so that the stud 55 engages a tooth on the worm gear 56 corresponding to theidesired' period of time that the operationis to be carried on as shown by the scale'ZO. The operation. is thus startedand will continue for the desired period whenit will be auto+ matically terminated as hereinbefore I de-- scribed.

It is apparent that this apparatus;v could.

be easily modified-without impairing or in any way altering its characteristic featuresby mounting the mortar on a stationary sup port and mounting the bracket on the mov able plate; @bviciusly such a modification would merely involve a few changes in the structure of the bracket and the use of such exp'edients as are well known to those skilled in the art. In either case the path traced by the pestle on the mortar alternately s irals' inwardl y and outwardly as" shown in ig. at so that material which tends to accumulate at the center of the mortar'is wiped off as" the pestle spirals inwardly and'when the pes tle alternately spirals outwardly the sidewall of the mortar is wiped o-fi. Thus all of the material in the mortar is thoroughly mixed without unmixed accumulations at the center and periphery of themortar such as have occurred in prior power-driven mixers.

too

From the foregoing is apparent that the apparatus herein disclosedprovides an efli cient and serviceable means for quickly'and homogeneously mixing or compounding materials of either a solid or liquid character, or ingredients comprisingliquids and solids; Such an apparatus-may also be usedfor grinding and pu-lverizing as well as other uses for which a mortar and pestle is ordinarily employed- This type of apparatus (built in a small size) is particularly adapted for mix dental. amalgams that itquickly and thoroughly kneads and mixes mercury and comprising mortar and pestle members,

means to retain said members in cooperative relation with each other, resilient means supporting one ofsaid members for universal tipping movement relative to the other whereby I the same are held in yielding engagement with each other, and mechanism for producing,between the mortar and pestle, a relative movement defining a paracentric path.

2. An apparatus of the character described comprising a mortar and pestle, means adapted to retainsaid mortar and pestle in operative relation, resilient means supporting the mortar for universal tipping movement whereby the same is held in yielding engagement with said pestle, and mechanism associated with said supporting means for impartinga movement thereto to cause the mortar to travel in a paracentric path relative to said pestle. V

3. Apparatus of the character described comprising mortar and pestle members, means supporting said mortar for universal tipping movement, means for retaining said members in yielding cooperative relation with 7 each other, and means for producing, between tric paths.

said mortar and pestle, a relative movement defining paracentric paths.

4. Apparatus of the character described comprising mortar and pestle members, means for retaining said members in cooperative relation, resilient means supporting said mortar for universal tipping movement whereby said members are held in yielding engagement with each other, and mechanism. for producing, between said mortar and pestle, a relative movementdefining paracen- 5. Apparatus of the character described comprlslng a mortar and pestle, means for retaining said pestle 1n fixed cooperative relation to said mortar, resilient means supporting the mortar for'universal tipping movement whereby the same is held in yield-' ing engagement with said pestle, and means for imparting to said supporting means translating motion to cause'said mortar to travel in paracentric paths relative to said pestle.

6. Apparatus of the character described comprising'a mortar, a movable plate having resilient fingers engaging said mortar and supporting the same for universal tipping movement, a pestle disposed in fixed cooperative relation to said mortar, and means for imparting translating motion to said plate to cause said mortar to travel in paracentric paths relative to said pestle.

7 Apparatus of the character described comprising a mortar, a movable plate having resilient fingers supporting the mortar for universal tipping movement, a pestle disposed in fixed cooperative relation to said mortar, and means for moving said plate in paracentric paths relative to said pestle, said means comprising differential driving members associated with said plate, one of said members tending to move said plate in a circular path, and the other tending to move said plate in a rectilinear path.

8. Apparatus of the character described comprising a base, a mortar, a movable plate supporting the mortar for universal tipping movement, a bracket pivotally mounted on said base, a pestle mounted in said bracket and adapted to be swung into fixed cooperative relation to said mortar, and mechanism associated with said plate for moving said mortarin curvilinear paths relative to said pestle.

9. The combination of mortar and pestle members, means for holding the members in operative relationship yieldingly to permit one member to move in any direction laterally of the axis of the mortar in response to lateral pressure from the other member, and means for producing relative movement between the members such that the pestle traces over the mortar a path which alternately spirals inwardly throughout a plurality of turns and then outwardly throughout a plurality of turns.

Signed by me at. Belmont, Massachusetts this 30 day of December, 1930.

. WILLIAM A. PERVIER. 

